Activating magnetoelectric optical properties by twisting antiferromagnetic bilayers

Cluster-assembled superatomic crystals for chirality-dependent charge-to-spin conversion

“…A wide range of intriguing phenomena have been observed in chiral molecules, nanoparticles, and assembled nanostructures, such as asymmetric catalysis, chiroptical activity, and chirality-induced spin selectivity [1][2][3][4][5][6] . Compared with molecular systems, explorations of chiral crystals are still evolving 7 , such as twisted bilayers 8,9 and molecule-assembled chiral materials 5 . Import of chirality to crystals leads to a finite set of possible symmetries, which enforce exotic transport, magnetic, and topological quantum properties, such as non-reciprocal electron transport 10 , skyrmions 11,12 , and Kramers-Weyl fermions 13 .…”

Magneto-optical Kerr Effect in Ferroelectric Antiferromagnetic Two-Dimensional Heterostructures

“…1,2,[29][30][31][32][33] Recent studies have shown that MOKE can also be found in 2D antiferromagnetic materials. 6,7,34,35 Parallel to 2D magnets, also 2D ferroelectric materials, such as In 2 Se This provides a promising route for electric field manipulation of the magneto-optic effects without modifying the underlying magnetic structure in antiferromagnetic heterostructure (HS). 2D HSs hold enormous potential for many applications since they can be assembled layer-by-layer to realize or to engineer desired physical properties.…”

“…1,2,29−33 Recent studies have shown that MOKE can also be found in 2D antiferromagnetic materials. 6,7,34,35 Parallel to layered magnets, also, 2D ferroelectric materials, such as In 2 Se 3 36 and CuInP 2 S 6 , 37 have received great attention. Inversion symmetry ( ) is broken in ferroelectrics by the presence of spontaneous polarization.…”

“…Recently, two-dimensional (2D) materials have been heavily studied because they show interesting physical properties different from bulk systems and can be exploited for miniaturized nanoelectronic components. − In particular, monolayer CrI 3 , one of the first experimentally synthesized low-dimensional magnets, has opened a new era in the study of 2D ferromagnetic materials . Soon after its discovery, many layered magnetic materials have been theoretically predicted and experimentally investigated. ,− MOKE is a surface-sensitive probe for magnetism, thus naturally attracting intensive interest from experimental and theoretical points of view for the study of magnetic 2D systems. ,,− Recent studies have shown that MOKE can also be found in 2D antiferromagnetic materials. ,,, …”

Layer Control of Magneto-Optical Effects and Their Quantization in Spin-Valley Splitting Antiferromagnets

“…For a 2D system ( σ yz = 0, σ zx = 0), the MOE is also suppressed by some scriptO symmetries [e.g., scriptO may be M x , M y , C 2 x , and C 2 y ] as well as limited by some combined scriptTS symmetries [e.g., scriptS may be M z , C 2 z , C 3 z , C 4 z , C 6 z )] due to the odd property of σ xy under these symmetries . Hence, by breaking above symmetries, MOE may also emerge in more commonly available collinear AFMs. − From the nanoscience application perspective, it is much desirable to enrich the MOE family in 2D collinear AFMs because of the emergent valley-indexes, − layer physics, ,− and multiferroic order. − Importantly, it is highly desirable to realize the long-sought spin-splitting in 2D AFMs, which has triggered extensive attention recently benefiting from the versatile development of altermagnetism. − …”